This invention relates to construction vehicles of the type having a material handling implement, and more particularly, to an improved stabilizer arm assembly for laterally supporting the vehicle and raising the wheels of the vehicle off the ground during operation of the material handling implement.
Many types of construction vehicles have stabilizer arms, or outriggers, which extend downwardly and outwardly from the frame sides during operation of their material handling implements, to engage the ground to laterally support the vehicle against tipping, and to anchor the vehicle to the ground by raising the wheels at the end of the vehicle having the material handling implement off the ground. For example, in a vehicle having a material handling implement, such as a backhoe, operatively connected to the rear end of the vehicle, a stabilizer arm is positioned generally adjacent and rearwardly of each of the rear wheels. It has also been found advantageous under some working conditions to mount stabilizer arms at the front end of the vehicle. U.S. Pat. Nos. 3,376,984; 3,951,281; 3,955,695; 4,026,428 and 4,286,803 disclose some typical arrangements of stabilizer arms.
A stabilizer arm typically has one end pivotally connected to the frame about a fixed stabilizer pivot point for movement between a ground engaging support position, extending laterally outward of the wheel, and a generally upright transport or storage position. To move the stabilizer arm between its support and transport positions and to apply a downward force on the stabilizer arm when in the support position to lift the vehicle off the ground, various power sources can be used. A common power source used in construction vehicles is a fluid ram, such as a hydraulic cylinder and piston rod assembly. Usually, one end of the fluid ram is pivotally mounted to the frame of the vehicle about a fixed pivot axis and the other end operatively connected to the stabilizer arm.
The typical stabilizer arm when in its support position extends laterally outward of the longitudinal center line of the vehicle frame by a fixed distance. In most instances this distance is selected to provide adequate stability for the vehicle under most operating conditions. However, under certain operating conditions it has been found to be desirable to either increase or decrease the distance which the stabilizer arm extends outward of such longitudinal center line. For example, when the vehicle is working near an obstruction, such as a roadway or building, it is necessary to position the end of the stabilizer arm close to the wheel and nearer to such longitudinal center line and when the vehicle is operating on a hillside, or the material handling implement is sideshifted, it is desirable to position the end of the stabilizer arm farther from the wheel and the longitudinal center line than is possible with typical stabilizer arms.
It is therefore desirable to provide a stabilizer assembly which permits the selective positioning of the end of the stabilizer arm relative to the wheel and longitudinal center line of the vehicle frame. One such assembly is disclosed in U.S. Pat. No. 3,550,795. In this assembly the inboard end of the stabilizer arm is pinned to the frame in one of two preselected positions. In order to reposition the outboard end of the stabilizer arm it is necessary that the operator manually repin the inboard end of the stabilizer arm. Further, this assembly only permits the positioning of the outboard end of the stabilizer arm in one of two positions. Under certain operating conditions it is desirable to precisely position the outboard end of the stabilizer arm in a specific relationship to the vehicle wheel.